Ultrafast Gates for Single Atomic Qubits

TL;DR

This paper demonstrates ultrafast single-qubit gates on a trapped atom using shaped femtosecond laser pulses, achieving high fidelity and extremely short operation times within the strong excitation regime.

Contribution

It introduces a method for performing ultrafast, high-fidelity single-qubit gates on atomic qubits using shaped femtosecond laser pulses, surpassing previous speed limitations.

Findings

Pi rotation in less than 50 ps

Population transfer exceeds 99%

Gate operation within the strong excitation regime

Abstract

We demonstrate single qubit operations on a trapped atom hyperfine qubit using a single ultrafast pulse from a mode-locked laser. We shape the pulse from the laser and perform a pi rotation of the qubit in less than 50 ps with a population transfer exceeding 99% and negligible effects from spontaneous emission or ac Stark shifts. The gate time is significantly shorter than the period of atomic motion in the trap (Rabi frequency / trap frequency > 10000), demonstrating that this interaction takes place deep within the strong excitation regime.